4-hydroxy-2-trifluoromethylbenzaldehyde

106312-36-1

1243395-68-7

The general procedure for the synthesis of 4-hydroxy-2-trifluoromethylbenzaldehyde using 2-trifluoromethyl-4-methoxybenzaldehyde as a starting material was as follows: boron tribromide (1.39 mL, 14.7 mmol) was dissolved in 5 mL of dichloromethane (DCM) at -78 °C and added slowly and dropwise to a 2-trifluoromethyl-4-methoxybenzaldehyde (2.0 g, 9.8 mmol) containing a 20 mL of DCM solution. The reaction mixture was stirred at room temperature for 15 hours. Upon completion of the reaction, the reaction was quenched with ice water and extracted with DCM. The organic phases were combined and washed sequentially with sodium bicarbonate solution, water and saturated saline, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography, and the eluent was mixed solvent of petroleum ether-ethyl acetate to obtain 4-hydroxy-2-trifluoromethylbenzaldehyde as a brown liquid in 91% yield. The structure of the product was confirmed by 1H-NMR (400 MHz, DMSO-d6): δ 10.035 (s, 1H), 7.984-7.963 (d, 1H, J = 8.4 Hz), 7.193-7.158 (m, 2H) ppm.